Broaching apparatus



Sept. 5, 1133. H. T. JONES ET AL, 9

BRQACHING APPARATUS Filed Dec. 29, 1930 HIS A TTORNEY.

Patented Sept; 5, 1933 UNITEE STATES PATENT 4 P8, assignors toHuger-coll the Jersey City, N. 3., e corporation Jersey Company, oi NewAppiicotion Decemher 2t, 19% Seriol No. %,356

3 @leims. (@H. 9M3) This invention relates to breaching apparatus, butmore psrticulorly to spperstus oi this chorecter for breaching spiralflutes in the interior of hollow articles.

5 One object oi the invention is to assure the accurate fluting of sucharticles end another object is to enable formation of internal flutes ofshort lead of spiral.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawing accompanying this specificstion and in which similarreference characters refer to similar parts,

Figure l is e longitudinal elevstion, portly I broken away, of as powerdevice equipped with breaching apparatus constructed in eccordence withthe practice of the invention,

Figure 2 is an enlarged sectionel elevation of the breaching apparatusand a. portion of the so power device, and

Figure 3 is a transverse view taken through Figure 2 on the line's- 3looking in the dime-- tion indicated by the arrows.

Referring more particularly to the drawing and at first to Figure l, Arepresents o power device shown for illustrative purposes. es shydreulic press of the horizontal type having to main frame B end ocylinder 0 into the ends oi which pressure fluid may be admitted in anyworking implement, such es s breech J, end for holding sold broochagainst rotation.

The breech J is illustrated as being of the type intended for formingspirel flutes in the interior of on article, such cs thst designated byK, end is provided clone the length thereof with alternate series oiteeth L end pilots 0 in which the cutting teeth L and the pilots 0 oneprovided with flutes P of the some lend end which flutes correspond tothe lord oi the flutes intended to be formed in the srticle The die--tence of the bottom surfaces Q of the flutes P irem the loneitudinelaxis of the breech J is the some throughout the entire length of thehroech irrespective oi the number oi pilots and series of cuttii'heteeth. The outer diameters of the cutting teeth end the pilots decreasehow-= ever, in the direction of the leading pilot, es for instance, thatpilot P ediecent the body or-shenlr portion "it of the brosching tool J.The teeth P are so spoced with respect to the pilots I? end the pitch ofthe teeth is such that ample chip spaces 8 will exist eround the bodyportion of the on brooch.

In accordance with the present invention a, holder designated generallyby T is provided for supporting the article K with respect to the breechJ. The holder T is journslled in s support cs plate U which is in thisinstance clemped to a bracket V of the power device A, as by means of eclamp piste W bolted to the bracket V.

The bracket V has a. bore X err-singed coexielly with the red E and thesupport ple'te U is provided with a. boss Y which extends into the boreX to centralize sold bearing plate with respect to the rod E andtherefore also to the breach J.

, The holder '3 is shown us being in the form of a. sleeve Z which isjournelled in the bearing plate U and is provided with e poir of thrusthearings h seated in recesses c in the opposite ends of the beeringplete U.

On the front end of the holder T is o head d having s. shoulder e toseat against the adjacent so thrust bearing 2). The opposite end of theholder T is threaded externally to accommodate 9, nut 1 which setsagainst the other thrust beerine b and serves to clamp the holder T andthe thrust hearings to securely in position. A iemb nut g is thresded onthe holder '1 to prevent unthresd= ing of the nut f.

Within the holder '1 is e bushing it to slidebly receive the orticle K,end in the well of the holder T and extending through the bushing h is sset to screw 5 whereby the erticle K my be clumped fixedly in thebushing it.

Moons ore provided ior efiectihg rotery move-: merit of the holder, Tand the article K in sccordsnce with the lead oi the flutes in thebreech o5 J in order to breech accurately termed flutes within theorticle K end of o leed corresponding to the'loed oi the flutes P in thebreech. To this end as guide k is disposed within s cevity o in thefront end of the holder I end, in ice the operative position, iss'dspted to sent against the adj-scent end of the erticle K to assist inholding said article immoveble in the holder T.

The breech J is guided by the guide bushing it end to this end the guidebushing is provided with flutes p to define ribs c which extend into theflutes p oi the breech J. The flutes p ore of sufiicient depth toprevent contscthetween the bottom surisces oi the flutes p and theperipheral surfeces of the teeth L sudthe pilots O of the no breach .1,irrespective of the number of series of teeth L on the breach or on aseries of breaching tools forming a set.

On the inner end of the ribs q are bearing surfaces 1- which seatagainst the bottom surfaces of the flutes P in the broach J toaccurately centralize the broach with respect to the article K. On theouter end of the guide bushing k is a head s which is preferably groovedto form radial projections t thus providing a convenient grip portionwhich may be grasped for disposing the guide bushing k in the assembledposition in the holder T.

' In order to assure against accidental displacement of the guidebushing It said guide bushing is provided with a spiral groove u in theperiphery of the extension 12 which lies within the holder T, and in thehead d of the holder is disposed a pin w which extends into the spiralgroove u to prevent unauthorized endwise movement of the guide bushingk. I

The method of operation is as follows: with the article K disposed inthe holder T and clamped in position by the set screw j and with theguide bushing k disposed in the holder T in such wise that the spiralgroove u will be engaged ,by the pin w, the broach J may be insertedthrough the guide bushing k and the article K, it being of courseassumed that the said article K is hollow.

The shank of the broach J may then be inserted in the chuck H andsuitably clamped thereto. If then the power device A is setin operationthe broach J will be gradually drawn through the article K and throughthe guide bushing k. The ribs q of the guide bushing will, by thecontact with the flutes P in the broach and by seating against the endof the article K, cause the entire holder T to be rotated in accordancewith the lead of the flutes P. The teeth L of the broach' will then cutflutes within the article K of identically the same lead and the sameconformation as the article K the guide bushing k may be removed byturning said guide bushing in the direction necessary for disengagingthe spiral slot u from the pin w. The set screw i may then be unscrewedto release the arrticle K which may be readily removed from the bushing12.. i

We claim:

1. Broaching apparatus for forming spiral flutes in an articlecomprising a support, article holding means journalled in the support, anonrotating spirally toothed broaching tool adapted to be drawn throughan article intended to be fluted, and a guide extending into the holdingmeans and being seated against an article intended to be fluted, forholding such article in the holding means, and having flutes tointerlock with the teeth on the broaching tool for rotating the guideand an article in accordance with the lead of the teeth on the breachingtool thereby eflecting the formation of flutes in the article of thesame lead as the teeth.' g

2. Broaching apparatus for forming spiral flutes in an articlecomprising a support, an article holder freely rotatable in the support,a spirally fluted non-rotating broaching tool adapted to be drawnthrough an article intended to be fluted, a guide bushing extending intothe holder and pressing such article against the holder, spiral ribs onthe holder for engagement with the flutes in the tool, thereby effectingrotation of the holder in accordance with the lead of the flutes in thetool, and means on the ribs engaging the tool for maintaining the toolin coaxial alignment with the guide bushing.

3. Broaching apparatus for forming spiral flutes in an articlecomprising a support, an article holder freely rotatable in the support,a spirally fluted non-rotating breaching tool adapted to be drawnthrough an article intended to be fluted, a guide bushing extending intothe holder and pressing such article against the holder, and spiral ribsin the guide bushing engaging the flutes in the tool, thereby effectingrotation of the holder in accordance with the lead of the flutes in thetool, and bearing surfaces on the ends of the ribs to engage the bottomsurfaces of the flutes in the tool for maintaining the tool in coaxialalignment with the guide bushing.

HARRISON T. JONES. ROBERT MCELROY.

